CHAPTER XII. 



SOIL DEFICIENCIES. 



Any condition or defect of the soil which tends to prevent the 

 maximum production of crops, or to render it unsuitable for cul- 

 tivation, may be termed a soil deficiency. Soil deficiencies may 

 be physical or chemical. 



Physical Deficiencies. These are mentioned here merely for 

 the sake of completeness. As regards physical deficiencies, a soil 

 may be too porous or too stiff, too wet or too dry, too cold or too 

 shallow. 



Fig. 55. Experimental plots, Gottingen, Germany, 

 Agricultural Institute. 



Cold soils, which are usually wet, when drained become warmer. 

 The depth of shallow soils may be increased by plowing a little 



